Road widening trencher-loader unit



Jan. 7, 1969 R. D. MacDoNALD 3,419,975

ROAD WIDENING TRENCHER-LOADER UNIT Filed Dec. 25, 1965 v f y `shee'` l' of 2 ATTORNEY Jan. 7, 1969 R. D. MaODONALD ROAD WIDENING TRENCHR-LOADER UNIT Sheet Filed Dec. 25, 1965 INVENTOR. Pavmoc D. Nac DoNnLD `ATTORNEY United States Patent O 3,419,975 ROAD WIDENING TRENCHER-LOADER UNIT Raymore D. MacDonald, Hinsdale, lll., assigner to Westinghouse Air Brake Company, Pittsburgh, Pa., a corporation of Pennsylvania Continuation-impart of application Ser. No. 466,945, June 25, 1965. This application Dec. 23, 1965, Ser. No. 516,022 U.S. Cl. 37-8 3 Claims Int. Cl. B601: l/36; E02f 9/00 ABSTRACT F THE DISCLOSURE A trencher loader attachment for use with a selfpropelled prime mover and adapted to cut a trench in and to remove a strip of shoulder material from the edge of an existing roadway. The trencher loader attachment includes an elevating conveyor to receive the discharge from a feeding conveyor and chute assembly having a pivotally mounted idler sprocket which yieldably urges a portion of the feeder conveyor toward the bottom of the chute.

This application is a continuation-in-part of my copending application Ser. No. 466,945 tiled June 25, 1965.

This invention pertains generally to a trencher-loader attachment unit that is mounted on a self-propelled road maintenance machine for use in road widening operations, and more particularly pertains to a yieldable material feeding assembly for a trencher-loader apparatus adapted to dig a shallow trench in a road shoulder immediately adjacent an edge of an existing roadway to receive a pavement widening strip.

It has become the practice to prepare the subgrade for a road widening operation with a trencher-loader apparatus mounted on a conventional road maintenance machine such as a motor grader, a front end loader or the like. These trencher-loader units are generally independently powered, having suitable drive means to perform the various digging, loading and adjustment functions as required. Often, when digging a trench, hidden lumps of concrete, stones, and other debris are encountered in the shoulder, causing jamming or damage to the trencher unit.

Accordingly, a primary object of this invention is to provide a trencher-loader apparatus with a feeder conveyor assembly that is not easily jammed nor subjected to damaging stresses.

Another object of this invention is to provide a trencherloader unit with a feeder conveyor assembly that will promote a smooth flow of trenched material through the digging and conveying operations.

Still another object is to provide a trencher-loader unit with a feeder chain having a conveying run which is yieldably displaced relative to a material supporting surface to thereby allow the passage of lumps or other obstructions.

Yet another object is to provide a trencher-loader unit, having a feeder chain,` with yieldable tensioning means.

An additional object is to provide a trencher-loader unit with a conveying run of feeder chain which is adjustable relative to a material supporting surface of a cutter frame.

These and other objects of this invention will become apparent in the following specification when taken in connection with the accompanying drawings, wherein:

FIGURE 1 is a fragmentary perspective view showing a portion of a conventional motor grader, and illustrating a trencher-loader unit constructed in accordance with the improvements of the present invention operatively supported on it;

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FIG. 2 is a fragmentary side elevational view of the front end of the trencher-loader unit with certain parts thereof being broken away and other parts shown in section;

FIG. 3 is a cross sectional view taken substantially along the line 3-3 of FIG. 2 looking in the direction of the arrows; and

FIG. 4 is a fragmentary top plan view of the chain tensioning idler sprocket taken substantially along the line 4 4 of FIG. 3 looking in the direction of the arrows.

Referring now to FIG. l of the drawing, a trencherloader unit 10 is shown operatively attached to a road maintenance machine, in this instance a self-propelled motor grader 12. The motor grader 12 moves along an existing pavement or roadway 98 with the trencherloader attachment unit 10` disposed off to the side, to dig a trench .14 in a shoulder 16 immediately adjacent an edge '18 of the pavement 98. Adjustment means 3'10, in

the form of a gauge wheel running along the top surface of the roadway 98 is provided to set the trench depth and to tix the lateral angle of the cut.

The improved trencher-loader attachment unit 10 embodying the present invention comprises a main support assembly 60 pivotally mounted on the motor grader 12 for adjustment about an axis (not shown) extending generally longitudinally of the roadway 98. An engine 78, carried by the assembly 60, provides all power requirements for the trencher-loader attachment unit 10.

A cutter frame assembly 104 is pivotally connected for up and down movement with respect to the main support assembly 60, by horizontal hinge pin 102 extending at substantially right angles to the longitudinal axis of the roadway 98. As best shown in FIG. 3, the frame assembly 104 comprises a chute defined by a pair of radially spaced apart generally vertically disposed side plates 106, 108 having upper, out-turned anged plate portions 110, .1'12 and an inclined, bottom floor plate 114 which is also Well shown in FIG. 2.

It is desirable that the trencher-loader attachment unit 10 be able to dig trenches of different widths. To this end, a forward side plate 124 of the cutter frame assembly 104 is offset, outwardly, from the side plate 108 by a curved rear plate 126, which can readily be replaced by one of different width to vary the effective cutting width of a cutter device or box which is disposed adjacent the front end portion of cutter frame assembly 104.

The cutter device or box cuts sides of the trench 14 by beveled cutting blades 128, which are secured to the side plates 106 and 124 respectively. The bottom or floor of the trench 14 is cut by a bottom, beveled, hori- Zontal blade 132 fastened to the bottom lloor plate 114. Blades 128, 130, 132 should be readily removable for sharpening or replacement and create the U-shaped cutter device or box which denes the shape, width and depth of the trench 14.

An arrangement of conveyor assemblies is disposed in the chute of the trencher-loader attachment unit 10 to receive and convey material from the cutter device or box to the rear end portion of the cutter frame assembly 104 Whereat the material may be discharged therefrom.

The arrangement of conveyor -assemblies comprises a rst conveyor or spring loaded feeder conveyor assembly 152 positioned within the U-shaped cutter box or chute of the cutter frame assembly 104. The feeder conveyor 152 comprises an endless feeder chain 166 having spaced along the periphery thereof a plurality of laterally extending paddles, digging members or scraper blades 168 adapted to dig and to move trenched earth material 198 upwardly along the inclined oor plate 114 of the chute and to discharge it onto a second conveyor assembly which may comprise a conveyor belt 154 of an elevating conveyor assembly 156. The second or conveyor assembly 156 is mounted on the cutter frame assembly 104 and is adjustable for up and down and sidewise movement by means described in detail in the above-mentioned copending application Ser. No. 466,945.

The feeder conveyor chain 166 of the first conveyor assembly 152 is trained between a drive sprocket 164 and a driven sprocket 162. Sprocket 164 is keyed to and driven by a rear driving shaft 160 the ends of which are journaled in pillow blocks 161, 163 mounted atop the flanged plate portions 110, 112 (FIG. 3). A pair of forwardly extending feeder conveyor arms 174, 176 is pivotally mounted for up and down movement about the shaft 160; arms 174, 176 are interconnected and braced by cross tubes 178, 193.

The driven sprocket wheel 162 is keyed (by means not shown) on a forward shaft 158 which is rotatably journaled in pillow blocks 170, 172 carried on the undersides of arms 174, 176. Adjusting screws 171 threaded in lugs 173 provide for forward and backward adjustment of the shaft 158 to adjust the take-up and tension in the feeder chain 166.

Referring to FIG. 2, the forward end of the feeder conveyor assembly 152 is urged downwardly by a spring biasing means 180 compressed between the forward upper surface of feeder arm 174 and a large washer 182 and nut 186 on the upper end of a rod 184 fastened by a pin 188 at its bottom end to a bracket 146 on side plate 106. Nut 186 provides adjustment for the compression spring 180.

A stop 185 on feeder conveyor arm 174 engages upper flange portion 110 of side plate 106 to limit the dowr1 ward movement of the feeder conveyor assembly 152. Shims 187 are provided between stop 185 and flange 110 to adjust the minimum spacing between sprocket wheel 162 and the bottom oor plate 114.

Structure is provided for mounting the first or feeder conveyor assembly 152 on the cutter frame assembly 104 to enable the feeder conveyor assembly 152 to move relative thereto between a first position whereat normal quantities of material may be received and passed to the elevating conveyor assembly 156 and a second position whereat abnormal quantities of material may be received and passed on to elevating conveyor assembly 156.

The structure is best seen in FIGS. 2, 3 and 4 of the drawing, a chain adjusting and tensioning idler sprocket 189 is located near the discharge end of the bottom floot plate 114. Sprocket 189 is journaled on a support member 195 which comprises a pair of transversely spaced apart generally vertically disposed plates 250 between which the sprocket 189 is rotatably journaled, on an idle shaft 251. As shown in FIGS. 3 and 4, the plates 250 converge and join one another at a location 252. The top edges of plates 250 are interconnected by an angled plate 253 carrying an upwardly open, spring-receiving cup 209. The support member 195 has a pair of transverse tubular extensions 254, 254 which are journaled on a shaft 255 mounted between a pair of supports 256, 256 fastened to gussets 257, 257 on the bottom surfaces of the arms 174, 176.

A compression spring 197 is seated in the cup 209. The upper end portion of the spring 197 is seated in a retaining cup 205 carried by longitudinal brace members 201, 203 fastened between cross tubes 178, 193. A spring adjusting screw 199 is threadedly engaged within a plate 258 fastened as by welding across the undersides of braces 201, 203. The adjusting screw 199 extends into cup 205 and engages a disc 259 at the end of the spring 197 to adjust the compression of the spring 197 by suitable adjustment of the screw 199.

Endless chain 166 may be thought of as comprising five individual portions. The portion wrapped around the front driven sprocket wheel 162, performs a dislodging or digging operation in the shoulder material 16. The portion of chain moving along the length of the bottom floor plate 114, between the driven sprocket wheel 162 and the idler sprocket 189, serves as. a conveying run. A discharge portion of the chain 166 moves around the idler sprocket 189 and upwardly away from the trenched material 198 after it has been deposited on the conveyor belt 154. A drive portion is the chain linkage wrapped around the drive sprocket 164 and lastly a return portion connects the drive and dislodging portions together.

The scraper blades 168 of endless chain 166 are adjusted to travel a course parallel to and just clearing the surface of bottom floor plate 114, by a combination of adjustment means; namely; screws 171, shims 187, and screw: 199 reacting through spring 197. Screw 199 and spring 197 also establish the chain tension, while screws 171, 171 also provide for chain take-up.

In operation, the vertical cutting blades 128, and the horizontal cutting blade 132 of the cutter frame 104, slice through the shoulder 16, defining the sides and bottom of the trench 14 immediately adjacent the roadway edge 18. The scraper blades 168 on the feeder conveyor chain 166 ymince and tear the earth material 198 from the solids and drag it up the inclined bottom oor plate 114 and discharge it onto the receiving portion of elevating conveyor 156.

An important advantage of the present invention, involving the spring biased, pivotal mounting for the tensioning sprocket 189, is the ability to deflect the sprocket 189 out of the way of a stone carried up by the paddles 168. If a stone is brought up with the shoulder material, spring will compress as the forward sprocket 162 shifts upward to clear the stone. Similarly, at the back end of the feeder conveyor, spring 197 compresses to enable the tensioning sprocket 189 to shift upward and clear the stone for discharge onto the conveyor 154.

Elevating conveyor 156 may be positioned to discharge the trenched earth material 198 into a truck for disposal, or may be swung to discharge the trenched material beyond the trench to provide material for a new shoulder.

The crux of the present invention is that the bias of spring 197, in cooperation with the spring 180, provides inherently yieldable means enabling the entire length of the conveying run of the endless feeder chain 166 to give when an oversize stone or lump is carried up the trough 114. This prevents blockage and stopping of the machine with objectionable down time for the working crew.

Thus it will be seen that this invention provides a digging and conveying feeder assembly protected from impact and overloads during the dislodging and conveying of shoulder material, especially lump or other solids encountered in a trenching operation. Further, the conveying feeder assembly is not subjected to the usual breakage and jamming experienced by machines not accorded the lbenefits of this invention. An adjustable chain tensioning means is also provided and other adjustment means to position the conveying run of chain relative to the material supporting inclined oor plate.

I claim as my invention:

1. In a trencher-loader attachment unit for use in combination with a self-propelled prime mover, adapted to cut a trench in and to remove a strip of shoulder material from the edge of an existing roadway;

a main supporting frame mounted on the prime mover;

a cutter frame assembly pivotally mounted on the main supporting frame and having an inclined chute with a forward cutting edge for defining the shape and size of the trench;

a feeder conveyor assembly disposed on the cutter frame assembly and having an endless chain linkage in the chute extending between and about a rear driving sprocket and a relatively large front driven sprocket, the chain linkage having a plurality of outwardly extending scraper blades for moving material along the floor of the chute;

drive means for the drive sprocket including a drive shaft at the rear portion of the chute;

a pair of arms pivotally mounted on the drive shaft and extending forwardly therefrom, a shaft carried by the forward portion of the arms and supporting the driven sprocket;

spring biasing means -for the forwardly extending `arms urging the driven sprocket toward the oor of the chute;

an idler sprocket carried by the forwardly extending arms and engageable with the chain linkage between the driving and driven sprockets adjacent the floor of the chute; i

a second spring biasing means acting between the forwardly extending arms and the idler sprocket to tension the chain linkage and being effective to urge the idler sprocket toward the floor of the chute; and

an elevating conveyor carried by the cutter frame assembly in a `material receiving relation with the feeder conveyor assembly.

2. The structure of claim 1 yfurther characterized in that said idler sprocket is pivotally mounted on the for wardly extending arms.

3. The structure of claim 1 further characterized in that said idler sprocket is mounted close to and between said drive sprocket and said chute oor adjacent the discharge end of said chute.

References Cited UNITED STATES PATENTS 2,564,486 8./1951 MacDonald 198-10 2,696,287 12'/ 1954 Foust 198--8 2,703,953 3/1955 Altemus 171-120 X ABRAHAM G. STONE, Prim-ary Examiner.

S. C. PELLEGRINO, Assistant Examiner.

U.S. C1. X.R. 198-8 

